Carb leaking fuel on Choke, wont run!!!

[cksetzer]

Ok so here's what I got. 1973 Merc 200, 20hp with a type B carb. Motor Serial is 3671256. I took down the carburetor and soaked all metal parts, replaced all gaskets on the carburetor and fuel pump. Put it all back on. Set the idle screw 1 1/4 out of seat. Primed up the bulb. Now here is where it gets funky. I pull out choke button and attempt to pull. After the first pull fuel starts leaking out of the carb. If I shut off the choke, no leak. Now after 1 pull with choke, she tries to fire. 1 pull with no choke she fires but only for a second. Multiple attempts and choke adjustments yesterday I had her running for a minute or 2 but I had to keep choking on & off. I know I'm missing something. Another note, when I reassembled the carburetor I blew in the fuel pump a little with the carb right side up and air went through, upside down air did not. Or vice versa. Heck I cant remember. I just remember reading on here to test it that way to make sure the float needle was seating. So what are your guys though?? Do I need to tear her back down???

 

[cksetzer]

Re: Carb leaking fuel on Choke, wont run!!!

Any ideas????

 

[cksetzer]

Re: Carb leaking fuel on Choke, wont run!!!

Had guy from another forum say that if a choke is working really good then fuel will pour out the front of the Carburetor. I am now looking for a tester to check the spark gap. I will repost with my finds.

 

[cksetzer]

Re: Carb leaking fuel on Choke, wont run!!!

Tested the "spark". Lower cylinder has a spark of a 1/2" or better. Top cylinder has no spark at all. Bad coil???

 

[bktheking]

Re: Carb leaking fuel on Choke, wont run!!!

Does that motor have the phase maker ignition?

Could be bad points/condensor or wiring

 

[cksetzer]

Re: Carb leaking fuel on Choke, wont run!!!

This is what I know about the ignition system from seloconline. Type IV Ignition System Thunderbolt - Flywheel CD (one Coil Per Cylinder). I plan on doing a switch/swap of the coils and will post what I find.

 

[cksetzer]

Re: Carb leaking fuel on Choke, wont run!!!

Swapped the power leads to the coils and found that one lead is not delivering power to the coil. One wire shows a spark jump of 5/16" or better. One wire shows no spark on either coil. So this leads me to believe the coils are fine. Could it be the power pack??? Any other test to perform to double check a faulty power pack??? Or am I overlooking something with the coil???

 

[bktheking]

Re: Carb leaking fuel on Choke, wont run!!!

Read this- page 75

http://issuu.com/cdielectronics/docs/troubleshootingguide/76

This is your system, I suspect a bad switch box (short for powerpack)

 

[cksetzer]

Re: Carb leaking fuel on Choke, wont run!!!

Went out to check to the Ohms and the first thing that I seen was a corroded wire with the protective cover split opened.





The first pic is the wire it self, green wire. The 2nd pic is where its coming from. Its attached to the right side connection, on the pic, or if your looking at the motor from behind its on the right side. The third is the power pack which its running too. From the pic the wire comes in on the right side, feeding the power pack. Now do you think the wire can be salvaged, via cut and a new wire attached? Do you think this is causing the lack of power to wire feeding the coil? Can these power packs be rewired or just replace the unit???

 

[bktheking]

Re: Carb leaking fuel on Choke, wont run!!!

Repair the wire if you can going to the pack, good crimp connectors should work and then use heatshrink to seal them. Cut the bad section out and crimp new in, you can't solder as it's aluminum wire. Retest after that, it could be a major voltage drop out of the green wire causing it to only fire on 1 cylinder. This is a common issue with those Merc motors, aluminum wiring eventually corrodes. That wire feeds 150+ volts so it has to be in good shape to provide that level of power.